Here’s the phases of Facebook:
Phase 1. Harvard only.
Phase 2. Harvard+Colleges only.
Phase 3. Harvard+Colleges+Geeks only.
Phase 4. All those above+All People (in the social graph).
Phase 5. All those above+People and businesses in the social graph.
Phase 6. All those above+People, businesses, and well-known objects in the social graph.
Phase 7. All people, businesses, objects in the social graph
